How to Replace a Chainsaw Chain

What you'll need

• Scrench (screwdriver/wrench combo)
• Work gloves

The steps

1. 1

   Remove the bar cover and side panel

   Use the scrench to remove the bar nuts and pull off the side cover (also called the clutch cover). On most saws this exposes the bar mounting studs, sprocket, and chain tensioner. Set the nuts and cover aside where they will not get lost.

2. 2

   Release the chain tensioner

   Turn the chain tensioning screw counterclockwise to fully release tension. This gives the chain slack so it slides off the bar easily. On some saws the tensioner is on the side panel, on others it is between the bar studs.

3. 3

   Slide the old chain off the bar

   Lift the bar tip slightly and slide the old chain off the bar nose and sprocket. Wear gloves — even a dull chain has sharp edges. Pull the bar away from the saw body to fully remove it. Set the old chain aside.

4. 4

   Clean the bar groove and sprocket

   Use a flat-head screwdriver or bar groove cleaning tool to scrape packed sawdust out of the bar groove. Wipe the sprocket and bar mounting area clean with a rag. Check the sprocket teeth for wear — rounded or hooked teeth will chew up a new chain. Replace the sprocket if it is worn.

5. 5

   Thread the new chain onto the bar with cutters facing forward on top

   Lay the new chain around the bar. The cutting teeth on the top of the bar must face forward, away from you, toward the bar tip. On the bottom of the bar, the cutters face back toward you. If the chain is backward, it will not cut. Seat the drive links into the bar groove as you go.

6. 6

   Reattach the bar and tensioner

   Slide the bar back onto the mounting studs with the chain looped around the sprocket. Make sure the drive links engage the sprocket teeth. Replace the side cover and thread the bar nuts on finger-tight. Do not fully tighten yet — the bar needs to move for tensioning.

7. 7

   Adjust tension and tighten

   Turn the tensioning screw clockwise until the chain is snug against the bar. Test by pulling the chain at the top of the bar — it should lift about 1/8 inch and snap back. The drive links should stay in the groove. Hold the bar tip up while tightening the bar nuts fully. This prevents the bar from sagging and the chain from loosening during use.

Frequently asked questions

When should I replace the chain instead of sharpening it?

Replace the chain when the cutters are too short from repeated sharpening to cut effectively, when teeth are broken or damaged, when the chain has stretched so much that the tensioner cannot take up the slack, or when you see cracked or deformed drive links. A chain that has been sharpened 5 to 10 times is usually at the end of its life.

How do I match the right replacement chain?

You need three measurements: pitch (distance between drive links, usually 3/8 or .325 inch), gauge (thickness of the drive links, usually .050 or .058 inch), and drive link count (total number of drive links in the loop). These specs are printed on the old chain or in your saw's manual. All three must match exactly.

Does a new chain need a break-in period?

Yes. A new chain is slightly stiff and the rivets are tight. Run it at low speed for 1 to 2 minutes with bar oil flowing before making any cuts. This lets the chain stretch slightly and the rivets seat. After the initial run, stop the saw and recheck tension — new chains stretch noticeably during break-in and usually need retightening.

What happens if I install the chain backward?

A backward chain will not cut. The saw will spin the chain, but the smooth backs of the cutters contact the wood instead of the sharp edges. The saw produces smoke and sawdust instead of chips, and the chain overheats. If your saw seems to have lost all cutting ability after a chain swap, check the direction first.

Products you'll need

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